Ramaria is a genus of epigeous fungi common to the coniferous forests of the Pacific Northwest of North America. The extensively branched basidiocarps and the positive chemical reaction of the context in ferric sulfate are distinguishing characteristics of the genus. The genus is estimated to contain between 200-300 species and is divided into four subgenera, i.) R. subgenus Ramaria, ii.) R. subgenus Laeticolora, iii.) R. subgenus Lentoramaria and iv.) R. subgenus Echinoramaria, according to macroscopic,
microscopic and macrochemical characters. The systematics of Ramaria is
problematic and confounded by intraspecific and possibly ontogenetic
variation in several morphological traits. To test generic and intrageneric
taxonomic classifications, two gene regions were sequenced and subjected
to maximum parsimony analyses. The nuclear large subunit ribosomal DNA
(nuc LSU rDNA) was used to test and refine generic, subgeneric and
selected species concepts of Ramaria and the mitochondrial small subunit
ribosomal DNA (mt SSU rDNA) was used as an independent locus to test the monophyly of Ramaria. Cladistic analyses of both loci indicated that Ramaria is paraphyletic due to several non-ramarioid taxa nested within the genus including Clavariadelphus, Gautieria, Gomphus and Kavinia. In the nuc LSU rDNA analyses, R. subgenus Ramaria species formed a monophyletic Glade and were indicated for the first time to be a sister group to Gautieria. Ramaria subgenus Ramaria and Gautieria were derived from R. subgenus
Laeticolora, which formed a paraphyletic grade that included Gomphus.
Ramaria subgenus Lentoramaria species also formed a paraphyletic grade
in the nuc LSU rDNA analyses. The Phallales and Clavariadelphus were
indicated as sister taxa to the R. stricta complex and Kavinia and R. abietina
of R. subgenus Echinoramaria grouped with the basal species, R. pinicola, of
R. subgenus Lentoramaria. In the mt SSU rDNA analyses, Gautieria and Gomphus again nested within Ramaria; however, the Phallales were indicated as a sister taxon to the Gomphales. A single evolutionary origin of the terrestrial habit was inferred for Ramaria with the terrestrial species, R. rainierensis, bridging the gap between the lignicolous R. subgenus Lentoramaria and the terrestrial R. subgenus Laeticolora. Species concepts tested included R. amyloidea and R. celerivirescens both of R. subgenus Laeticolora that differ primarily in the presence of clamp connections. The results supported these two taxa as distinct, sister species. These analyses were consistent with the ramarioid morphology as ancestral for the Gomphales with unique derivations of the club, false truffle and gomphoid morphologies. / Graduation date: 2000
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/33357 |
| Date | 11 November 1999 |
| Creators | Humpert, Andrea J. |
| Contributors | Spatafora, Joseph W. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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